Terahertz Digital Chess-Board-Modulated Spread-Spectrum System for Radar and Communication Comprising 200 GHz Bandwidth

• Applicants: Professor Dr.-Ing. Frank Ellinger; Professor Dr.-Ing. Vadim Issakov; Professor Dr.-Ing. Robert Weigel
• Subject Area: Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 468818520

TIEMPO proposes the realization of an I/Q transceiver chipset for spread-spectrum digital noise radar operating in the frequency range from 220 GHz to 420 GHz. This corresponds to a record bandwidth of 200 GHz. In this project we innovate on the idea of the frequency modulated continuous wave (FMCW) comb radar, by proposing a concept that can be viewed as a digital radar counterpart to a frequency comb radar. To achieve the extremely wide bandwidth we propose a novel system architecture implementing a “chess-board spectrum division”. Thanks to an elegant system level solution, a single oscillator at a fixed frequency is sufficient to generate five local oscillator (LO) carrier frequencies to cover the entire bandwidth. Furthermore, due to the high-speed I/Q mixed-signal components in combination with the “chess-board” concept, we reduce the number of required transmit/receive channels by two. This architecture can also be used for communication systems, as the digital sequence is generated externally.This extremely wide bandwidth imposes difficult challenges at the circuit design level, which is the main focus of this proposal: (1) I/Q data converters with 8-bit resolution, 20 GHz bandwidth, and 40 Gbps data-rate; (2) I/Q transmitter and receiver operating above 400 GHz; (3) LO signal generation to cover the entire bandwidth; (4) on-chip antennas with 200 GHz bandwidth and high efficiency. These operation frequencies are very close or above fmax of the technology intended for experimental validation, which is the 22 nm FD-SOI (Fully-Depleted Silicon-On-Insulator) CMOS process of Globalfoundries. This requires novel circuit and system level approaches to circumvent technology limitations. To our knowledge, this is the first digital spread-spectrum radar transceiver concept proposed in this frequency range, and the first operating over a bandwidth of 200 GHz.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2314: INtegrated TERahErtz sySTems Enabling Novel Functionality (INTEREST)